CYTOLOGICAL EXAMINATION OF MICROSPORE DEVELOPMENT FOR MICROSPORE AND ANTHER CULTURE OF COCONUT (Cocos nucifera L.) cv SRI LANKA TALL

Production of double haploids through anther and microspore culture has aconsiderable potential for shortening the breeding cycle in coconut. Thedevelopmental stage of a microspore is a critical factor in androgensis andmicrospores at late uninucleate stage have been shown to be the mostsuitable stage for in vitro culture for many crop species. Routine cytological; examination of microspores for identifying the correct stage for culture istedious and time-consuming. In the present study, a correlation between themicrospore developmental stage and age of the spadix (in Sri Lanka Tallcoconut) in terms of weeks-before-splitting (WBS) was established forpractical convenience of anther and microspore culture. At the age of eightWBS, anthers consisted of microspore mother cells. Within one week, thesecells underwent meiosis and produced tetrads. The release of microsporesfrom tetrads could be observed in six WBS spadices. Microspores at late uninucleate stage, which is reported as the most suitable stage forandrogenesis, could be obtained from three WBS spadices.